1. Field of the Invention
The present invention relates to a novel tertiary aminoalcohol. The tertiary aminoalcohols per se are used as an emulsifier, epoxy hardener, urethane catalyst, flotation agent, extractant, additive for lubricating oil, and the like. Further derivatives of the tertiary aminoalcohols, such as quaternary ammonium salts, benzalkonium salts, carbobetaines and amine oxides can be used for various purposes. Particularly they can be converted into various derivatives, taking advantage of the characteristic structure thereof having a terminal alcohol, by modifying them through esterification, sulfation, phosphation, amination or halogenation.
The present invention relates to a novel polyurethane, a process for producing the same, and a process for producing a polyurethane foam. More particularly, the present invention is concerned with a process for producing a polyurethane which gives a polyurethane excellent moldability in mold filling substantially without the necessity for using a catalyst component commonly used for producing a polyurethane, a polyurethane produced by the process, a process for producing a rigid polyurethane foam excellent in mold filling, thermal insulation property and low-temperature dimensional stability, and a process comprising a spray step for producing a rigid polyurethane foam having excellent mechanical properties and adhesive properties whereby the reaction of a polyol with an isocyanate can sufficiently proceed at low temperature. Furthermore, the present invention is concerned with a process for producing a foamed-in-mold flexible polyurethane foam for use in furniture and automobile cushions, more particularly, a process for producing a flexible polyurethane foam by using a urethane feedstock containing a particular tertiary aminoalcohol and having an excellent high temperature moldability at the time of pouring of a urethane feedstock in mold foaming.
2. Description of the Related Art
The inventors of the present invention do not known the fact that amino alcohols having a tert-amino group in the main chain thereof and a process for producing it like that of the present invention have been disclosed in known publications except for an ethylene oxide or propylene oxide adduct of an amine.
As for polyamines, a process for producing a polyamine having a terminal amino group by reacting a diol with NH.sub.3 is disclosed in Japanese Patent Laid-Open Nos. 278528/1986 (Texaco) and 51646/1987 (W. R. Grace & Company), and a process for producing a polytertiary amine by the condensation reaction of a di-sec-amine with a diiodoaryl compound is disclosed in Japanese Patent Publication No. 29182/1989 (Xerox Corporation). Further a process wherein a polyalkylene polyamine is produced by the co-condensation of a lower diamine with hexamethylenediamine is disclosed in Japanese Patent Publication No. 311009/1987 (Nippon Oil Co., Ltd.), etc. As for the polyamine derivatives, a process wherein a polycation is produced by reacting a di-tert-amine with a dihalide is disclosed in Japanese Patent Publication Nos. 37242/1986 and 37243/1986 (L'Oreal).
However, tertiary aminoalcohols having a tert-amino group in the main chain skeleton thereof and a terminal hydroxyl group are utterly new compounds and no process has been known for the production thereof. If the production of such tertiary aminoalcohols is possible, the use thereof for a purpose different from that of ordinary amines and amine derivatives can be developed and, in addition, by the oligomerization or polymerization of the amines, characteristic properties different from those of the monomeric molecules can be obtained. Thus the development of a new use of the amines is expected.
On the other hand, polyurethanes are used in various industrial fields, such as elastomer, rigid foam, semirigid foam, flexible foam and microcellular foam, by virtue of the ease of control of molding density, hardness of products and various properties, and their excellent moldability. In producing these polyurethanes, it is a common practice to use a tertiary amine or an organometallic catalyst as a polyurethane producing catalyst in addition to a polyisocyanate component and a polyol component for the purpose of promoting curing or foaming, which enables a polyurethane to be produced on an industrial scale.
Among the polyurethane producing catalysts, tertiary amines are widely used because they are useful for controlling the balance of the reaction. In many cases, however, they have a strong irritating odor and cause skin irritation and therefore cause problems of the working environment and have a drawback that the odor lowers the value, in particular the sales appeal, of the product.
Further, when a rigid polyurethane foam or the like is molded by mold foaming for use in a refrigerator or a panel, an improvement in the mold filling relating to the fluidity of the resin within the mold is required, so that a method for lowering the density in a high yield has been desired in the art.
In recent years, the use of chlorofluorocarbons as a foaming agent has become legally regulated for the protection of the ozonosphere, and trichlorofluoromethane (R-11), which has hitherto been used for the production of a rigid polyurethane foam, is among the substances subject to regulation. This brings about a problem of the necessity for reducing the use of trichlorofluoromethane. Examples of the reduction means proposed in the art include increasing the amount of water used to reduce the amount of trichlorofluoromethane (the so-called "chlorofluorocarbons-poor formulation") and one wherein use is made of 1,1-dichloro-2,2,2-trifluoroethane (R-123), 2,2-dichloro-2-fluoroethane (R-141b), chlorodifluoromethane (R-22), 1,1,1-chlorodifluoroethane (R-142b) or 1,1,1,2-tetrafluoroethane (R-134a) having an ozone destruction factor (ODP) smaller than that of trichlorofluoromethane.
In the chlorofluorocarbons-poor formulation wherein the amount of water used as a foaming agent is increased, the increase in the amount of water inevitably accelerates the reaction of water with the polyisocyanate component. This causes the amount of formation of a urea bond derived from the evolution of carbon dioxide to be increased, so that the balance between the foaming reaction and the resinification reaction is lost, which causes the mold filling of the polyurethane foam to be significantly lowered. The use of 1,1-dichloro-2,2,2-trifluoroethane or 2,2-dichloro-2-fluoroethane instead of trichlorofluoromethane makes it necessary to increase the amount of use of water, because the low temperature dimensional stability, compressive strength and mold filling are lowered thereby. This, however, causes the mold filling to be further lowered.
The rigid polyurethane foam produced by a process comprising a spray step (a spray type rigid polyurethane foam, hereinafter) is used mainly for the thermal insulation of the internal wall and ceiling of houses and the thermal insulation of tanks. A special foaming machine is used for the foaming work of the spray type rigid polyurethane foam. An air spray foaming machine is a system wherein compressed air is introduced into a mixing gun, while an airless foaming machine is a system wherein a feedstock is introduced into a mixing gun through the use of a lightweight compressor and then sprayed. A liquid mixture comprising a polyol component and an isocyanate component is sprayed on a face of an article through the use of the above-described foaming machines, and a thermal insulation layer comprising a rigid polyurethane foam is formed on that face through the utilization of properties of the mixture which allow rapid thickening, foaming and forming a high-molecular weight polymer.
The above-described useful spray type rigid polyurethane foam has found an expanded application, however the increase in the amount of use thereof has brought about various problems. One of the problems is that the bonding strength between the foam and the adherend material is so poor, that the foam peels off or falls down with the lapse of time to impair the thermal insulation effect, so that dewing becomes liable to occur.
Further, the regulation of the use of chlorofluorocarbons such as trichlorofluoromethane has brought about a tendency that the amount of incorporation of water in the foaming agent is increased, which renders the above-described problems more serious. Specifically, when the amount of the chlorofluorocarbon subject to regulation is reduced by increasing the amount of incorporation of water, the agglomeration caused by a urea bond formed by the reaction of water with the isocyanate violently occurs and further the boundary between the urethane foam and the adherend or the surface of the foam suffers from less accumulation of the heat of reaction, which brings about drawbacks such as a lack in the self-bonding strength which is the most important property of the spray type rigid polyurethane foam and an increase in the fragility. This tendency becomes conspicuous in conducting the spraying at a relatively low temperature of 5.degree. C. or below.
The flexible hot mold foam is produced by blending and sufficiently mixing a polyether polyol, a polyisocyanate, a foaming agent, a silicone foam stabilizer and a catalyst with each other, pouring the mixture into a mold and then heating the mixture to allow a reaction to proceed. In this case, after the temperature of the mold is adjusted to 35.degree. to 45.degree. C., a urethane feed-stock is poured into the mold to conduct foaming and cured in a furnace at 160.degree. to 200.degree. C., and the cured foam is demolded. The reason why the temperature of the mold is adjusted to 35.degree. to 45.degree. C. resides in that when it is below 35.degree. C., an increase in the foam density and insufficient curing of the foam are liable to occur, and further the time taken from the pouring to the demolding is lengthened, which hinders the production of the foam. When the temperature of the mold exceeds 45.degree. C., a crack occurs within the foam, so that good products can not be obtained. Although trichlorofluoromethane is used in the production of a foam having a low density and a low hardness, it is desired to reduce or discontinue the use of trichlorofluoromethane for the reasons mentioned hereinabove.
Therefore, if a good foam can be uniformly produced at a mold temperature of 45.degree. C. or above, the step of cooling the mold after the demolding of the foam in a foam production line can be remarkably omitted, which contributes to the prevention of energy loss. Further, the foam produced at a higher mold temperature has a lowered density due to an enhancement in the foaming efficiency. In attaining the same density as that of the foam at an ordinary mold temperature, the amount of the foaming agent can be reduced, whereby the use of the chlorofluorocarbons subject to regulation can be reduced or discontinued.